Definition for Ground Loop

A phenomenon caused by having more than one possible path to ground for a device or devices, so the local grounds at each end of a length of cable are at a different ACFullcompass LogoDefinition:
AC (Alternating Current): Current whose electrical flow alternates between positive and negative quadrants, and whose magnitude varies periodically. Alternating current is used in most commercial power transmission, and is also the basis of audio or video signals.
potential. This can cause humFullcompass LogoDefinition:
An undesired continuous signal caused by AC electrical power, typically 60/50 Hz and its harmonics.
and noise between two separated pieces of equipment with unbalanced connections. Standard solutions include lifting the ground connection between the equipment, adding an isolation transformerFullcompass LogoDefinition:
A passive electromagnetic device that uses one or more coils of wire to isolate or split signals. Also may convert impedance and voltage levels. May be used to eliminate ground loops, reduce Rf interference or crosstalk.
, coupling audio signals optically, or (not recommended) lifting the ground at one of the AC connections.

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